1. Field of the Invention
This invention relates in general to equipment for inserting a resilient sealing strip into a groove in a concrete surface, and in particular to a machine that draws a supply of the strip from a reel.
2. Description of the Prior Art
Grooves are formed in concrete surfaces, such as airports or highways, at regular intervals. These grooves allow for expansion and contraction of the concrete with the seasonal temperature changes. To avoid deterioration, the grooves need to be sealed from water. Strips of resilient material of various types are forced into the groove to provide the sealant.
Machines have been used for inserting the strip into the groove. These machines have a reel mounted to a frame that is rolled on wheels. An insertion disk presses the strip into the groove. The strip is normally a compression type seal made of a rubber material such as neoprene.
In U.S. Pat. No. 4,699,540, issued Oct. 13, 1987, Robert M. Gibbon, a silicone rubber tube is used as a sealing strip. This tube is sealed in the groove by a liquid room temperature vulcanizing (RTV) sealing material. One difficulty in laying the silicone rubber tube is that it has a somewhat tacky surface when located on the supply reel. As the tube is pulled from the supply reel, it stretches. If the tube is pushed into the groove under a stretched condition, it will later begin to shrink back to its original length. This would result in it being too short. The prior art neoprene strips are much stiffer and do not stretch as much under the same conditions.
U.S. Pat. No. 3,364,828, L. L. Shope et al, shows a machine for inserting a compression type sealing strip into a groove. This machine has pinch rollers 41, 42 which are driven at the speed that is fixed relative to the speed of the wheels. The speed is selected to draw the strip off at the same rate that the machine moves over the ground.